Sweet Tony Soprano, “Mafia Mamma” is bad. And not just disappointingly bad, in the way of late-career James Cameron, or irritatingly puerile, like virtually anything featuring Roberto Benigni. No, “Mafia Mamma” is so wincingly awful it makes you question the professional bona fides of everyone who had a hand in greenlighting its existence. This probably sounds harsh. But, as someone who has long respected the work of the film’s director, Catherine Hardwicke – whose abilities were evident from the get-go with “Thirteen” and, five years later, the first and best entry in the “Twilight” troop – I was jarred. A clodhopping farce interrupted by seizures of cartoonish violence, Hardwicke’s latest outing posits that the best distraction from an empty nest and a cheating spouse is to dash to Italy and join the Cosa Nostra. At least, that’s what Kristin, a self-effacing California housewife, does when she’s summoned to the Roman funeral of her estranged grandfather, a Mafia don and learns that she is his designated replacement. Having recently waved her son off to college and surprised her no-count husband in flagrante, Kristin was hoping for – to paraphrase the sage advice of her best friend, played by a delightfully spicy Sophia Nomvete – an eat-pray-fornicate adventure.